1. Field of the Invention
The present invention relates to a multilayer identification card having an IC module arranged on a carrier element, the IC module being disposed in a cavity in the card and surrounded by elastic material. The invention also relates to a method of producing such an identification card.
2. Discussion of Background and Material Information
An identification card in which the integrated circuit in a cavity in the card is partially surrounded by an elastic embedding mass is described, for example, in German Offenlegungsschrift No. 22 20 721. In this known card, the circuit is surrounded only on three sides by an elastic mass, while the leads and connection points of the leads are rigidly fixed to the circuit in the card body. When the card is bent, the connection points between the leads and the circuit are thus especially endangered. German Offenlegungsschrift No. 22 20 721 explains, as far as the production of the identification card is concerned, that the circuit may be embedded, for example, a resilient patting material in.
Another identification card having an integrated circuit and a method for producing it are disclosed in German Offenlegungsschrift No. 30 29 939. In the case of this identification card, for example, so-called buffer zones in the form of intermediate layers are provided in the card compound before lamination. These layers have a lower softening point than the films conventionally used in card production and are elastic in a cold state. Even before the full laminating pressure takes effect on the carrier element or the IC module, the layers with a lower softening point soften and fill in the cavities present in the area of the carrier element. In this way, a homogeneous casing is formed around the carrier element, which can then take on the full laminating pressure.
In the case of the identification card proposed in German Offenlegungsschrift No. 30 29 939, cavities present in the area of the carrier element are filled in, during, or in the initial phase of, the laminating process, with the material of softend card layers additionally present in the laminate. This means that intermediate layers in the form of additional films or coatings, which soften at appropriate low laminating temperatures but must not have any effect, if possible, on the compound of card layers themselves, must be used for the production of the identification cards.